Cat-PECVD method, film forming apparatus for implementing the method, film formed by use of the method and device manufactured using the film

ABSTRACT

A non-Si non-C-based gas is heated by a thermal catalysis body provided in a gas introduction channel, and the heated non-Si non-C-based gas and a material-based gas comprising Si and/or C are separately introduced into a film deposition space through a showerhead having a plurality of gas effusion ports, and in the film deposition space, a plasma space is formed by a nonplanar electrode connected to a radio frequency power supply, thereby forming a film on a substrate. Formation of high-quality Si-based films and C-based films can thus be accomplished at high deposition rate over large area with uniform film thickness and homogeneous quality. Also, highly efficient devices including photoelectric conversion devices represented by solar cells can be manufactured at low-cost by the use of such films.

[0001] This application is based on application No. 2002-067445 filed inJapan, the content of which is incorporated hereinto by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a Cat-PECVD method, a filmforming apparatus for implementing the method, a film formed by use ofthe method, and a device manufactured using the film. In particular, thepresent invention relates to a technique capable of forming high qualitySi-based thin films, which are used in photoelectric conversion devicesas typified by Si-based thin film solar cells, at high deposition rateover large area with uniform film thickness and homogeneous filmquality.

[0004] 2. Description of the Related Art

[0005] High-quality, high-deposition rate film forming techniques arecrucial for improvement in performance and cost reduction of variousthin film devices. In particular, for Si-based thin film solar cellsthat are the typical of photoelectric conversion devices, large-areafilm formation is also required in addition to high-quality,high-deposition rate formation of Si-based films.

[0006] Meanwhile, to classify broadly, there have been two methods knownas low temperature film forming techniques: the PECVD (plasma-enhancedchemical vapor deposition) method and the Cat-CVD (catalytic chemicalvapor deposition) method (the HW (hot wire)-CVD method follows the sameprinciples). For the both techniques, research and development work hasbeen intensively continuing focusing on the formation of hydrogenatedamorphous silicon films and crystalline silicon films includingmicro-crystalline, mono-crystalline and poly-crystalline silicon films.Hereinafter, “crystalline silicon” is referred to silicon includingmicro-crystalline, mono-crystalline and poly-crystalline silicons. FIG.4 illustrates a PECVD apparatus as conventional art 1, and FIG. 5illustrates a Cat-CVD apparatus as conventional art 2.

[0007] In FIG. 4, there are shown a showerhead 400, a gas introductionport 401, gas effusion ports 402, a plasma space 403, an electrode 404for plasma generation, a radio frequency power supply 405, a substrate406, a substrate heater 407, and a vacuum pump for exhausting gas 408.

[0008] In FIG. 5, there are shown a showerhead 500, a gas introductionport 501, gas effusion ports 502, an active gas space 503, a thermalcatalysis body (catalyzer) 504, an electric power source 505 for heatingthe thermal catalysis body, a substrate 506, a substrate heater 507, anda vacuum pump for exhausting gas 508.

[0009] To take a case where a Si film is formed using SiH₄ gas and H₂gas as an example, in the PECVD apparatus shown in FIG. 4, the gasesintroduced from the gas introduction port 401 provided at the showerhead400 are directed through the gas effusion ports 402 into the plasmaspace 403, where the gases are excited and activated to yield adecomposed species, which is deposited on the opposed substrate 406 toform a Si film. Here, the plasma is generated by means of the radiofrequency power supply 405.

[0010] On the other hand, in the Cat-CVD apparatus shown in FIG. 5, thegases introduced from the gas introduction port 501 provided in theshowerhead 500 are directed through the gas effusion ports 502 into thefilm deposition space, where the gases are activated by the thermalcatalysis body 504 provided in the space, thereby to yield a decomposedspecies, which is deposited on the opposed substrate 506 to form a Sifilm. Here, the heating of the thermal catalysis body is accomplished bymeans of the heating power source 505.

[0011] However, these conventional techniques have the followingproblems:

[0012] In order to achieve high-deposition rate film formation by thePECVD method, it is necessary to promote the decomposition of the SiH₄gas and H₂ gas by increasing the plasma power. However, increase of theplasma power on the other hand leads to increase in ion bombardment onthe surface for deposition and promotes generation of higher-ordersilane species that leads to formation of powder. For this reason, thismethod cannot avoid incurring adverse factors that hinder theimprovement of the quality.

[0013] Here, instead of increasing the plasma power, when the plasmaexcitation frequency is set to be in the VHF band or higher, thebombardment of ions is reduced because of the reduction of the plasmapotential. This is effective for the formation of high-qualityhydrogenated amorphous silicon films and crystalline silicon films.(Refer to J. Meier et al, Technical digest of 11^(th) PVSEC (1999) p.221, O. Vetterl et al, Technical digest of 11^(th) PVSEC (1999) p. 233.)However, sincethe formation of crystalline Si films requires sufficientproduction of atomic hydrogen, increasing the plasma power is inevitablefor film formation at a growth rate higher than a certain level, even ifVHF band frequencies are used. Accordingly, the above mentioned problemsare still unavoidable in such a case.

[0014] Also, increasing the hydrogen dilution rate, namely the gas flowratio (H₂/SiH₄), may be considered as a measure for increasing thedensity of atomic hydrogen without increasing the plasma power. However,this causes the partial pressure of the SiH₄ gas to decrease, whichworks contrary to the high-speed deposition. Therefore, also in thiscase, it is after all necessary to increase the plasma power so as topromote decomposition of SiH₄. The problems mentioned above aretherefore still unavoidable.

[0015] Meanwhile, increasing the pressure for film deposition may beconsidered as a measure for reducing the ion bombardment while allowingthe plasma power to increase. However, in such a case, the reaction togenerate higher-order silane species is accelerated, thereby failing toavoid factors deteriorating the film quality such as formation ofpowder.

[0016] On the other hand, in the Cat-CVD method, because of the nonuseof plasma, the aforementioned problem of ion bombardment does not arisein principle, and the formation of powder is minimal. Moreover, sincethe generation of atomic hydrogen is greatly accelerated in this method,the formation of crystalline Si films can be accomplished relativelyeasily and speedily. In addition, since there is no restriction inprinciple in enlarging the deposition area, this method has beenattracting growing attention. (H. Matsumura, Jpn. J. Appl. Phys. 37(1998) 3175-3187, R. E. I. Schropp et al, Technical digest of 11^(th)PVSEC (1999)p. 929-930)

[0017] However, under the present circumstances, temperature increase inthe substrate due to radiation from the thermal catalysis body isunavoidable. Therefore, stable formation of high quality films is notnecessarily easy. In addition, since SiH₄ gas is decomposed directly bythe thermal catalysis body, atomic Si is inevitably generated. Theatomic Si is unfavorable for formation of high quality Si films. Also,radicals such as SiH and SiH₂, which are resulted from the reaction ofthe atomic Si with H and H₂ in gas-phase, are unfavorable for formationof high quality Si films. Accordingly, it has been extremely difficultto form high-quality crystalline Si films.

BRIEF SUMMARY OF THE INVENTION

[0018] The present invention has been accomplished under thesecircumstances, and a primary object of the invention is to provide aCat-PECVD method capable of forming high quality Si-based films andC-based films over large area at high deposition rate with uniform filmthickness and homogeneous quality, a film forming apparatus forimplementing the method, a film formed by use of the method, and adevice manufactured using the film.

[0019] The “Cat-PECVD method” here refers to a CVD method whichintegrates the PECVD method and the Cat-CVD method, incorporating thecharacteristics of the both methods thereinto. The naming thereof isdone by the present inventors.

[0020] In the Cat-PECVD method according to the present invention, amaterial-based gas comprising a gas whose molecular formula includes Siand/or C and a non-Si non-C-based gas comprising a gas whose molecularformula excludes Si and C that is heated by a thermal catalysis bodyprovided in a gas introducing channel are passed separately through ashowerhead having a plurality of gas effusion ports to be introducedinto a film deposition space and mixed together, where a plasma space isformed by a nonplanar electrode connected to a radio frequency powersupply, thereby a film is deposited on a substrate.

[0021] The “nonplanar electrode” here refers to an electrode having anantenna-style, an antenna-style (ladder-style), or a spoke-stylegeometry.

[0022] A film forming apparatus according to the present invention is anapparatus for implementing the aforementioned Cat-PECVD method, whichcomprises: a first introduction channel for introducing a non-Sinon-C-based gas comprising a gas whose molecular formula excludes Si andC; a thermal catalysis body provided in the first introduction channelfor heating the non-Si non-C-based gas introduced thereinto; a secondintroduction channel for introducing a material-based gas comprising agas whose molecular formula includes Si and/or C; a showerhead having aplurality of gas effusion ports for directing the material-based gas andnon-Si non-C-based gas heated by the thermal catalysis body into a filmdeposition space separately from each other; and a nonplanar electrodeconnected to a radio frequency power supply for forming a plasma spacein the film deposition space.

[0023] In the Cat-PECVD method and the film forming apparatus accordingto the present invention, at least the non-Si non-C-based gas is heatedby the thermal catalysis body which is provided in the channel forintroducing the gas and connected to a heating power source. Thematerial-based gas and the non-Si non-C-based gas are separatelyintroduced into the film deposition space through the showerhead havinga plurality of gas effusion ports. It is possible to form a plasma spacein the film deposition space by the nonplanar electrode that isconnected to the radio frequency power supply, thereby a film can bedeposited on the substrate. Accordingly, formation of high-qualitySi-based films and C-based films can be accomplished at high depositionrate over large area with uniform film thickness and homogeneous filmquality.

[0024] In addition, because of the thermal catalysis body, the amount ofdecomposition and activation of the non-Si non-C-based gas can be freelycontrolled independently from the amount of decomposition and activationof the material-based gas by plasma. Since the material-based gas isactivated solely by the plasma, generation of unfavorable radicalscaused by the thermal catalysis body can be avoided.

[0025] The use of the thermal catalysis body has a gas heating effect asa secondary effect, which suppresses the reaction in gas-phase thatproduces higher-order silane species. In addition, the use of theshowerhead further facilitates the formation of large-area films withuniform thickness and homogeneous quality.

[0026] Furthermore, by the use of the film formed by the Cat-PECVDmethod according to the present invention, highly efficient devicesincluding photoelectric conversion devices represented by Si-basedthin-film solar cells can be manufactured at low cost.

[0027] The present invention is hereinafter described more in detailwith reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 illustrates a first embodiment of the method according tothe present invention.

[0029]FIG. 2 illustrates a second embodiment of the method according tothe present invention.

[0030]FIG. 3 illustrates a third embodiment of the method according tothe present invention.

[0031]FIG. 4 illustrates a first example of a conventional method.

[0032]FIG. 5 illustrates a second example of a conventional method.

[0033]FIG. 6 illustrates one example of the nonplanar electrode in themethod according to the present invention.

[0034]FIG. 7 illustrates another example of the nonplanar electrode inthe method according to this invention.

[0035]FIG. 8 illustrates an embodiment of the CVD apparatus according tothe present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0036]FIG. 1 illustrates a film forming apparatus for implementing theCat-PECVD method according to a first embodiment of the presentinvention. In this film forming apparatus, a showerhead and a nonplanarelectrode for plasma generation are separately provided.

[0037] In the drawing, there are shown a showerhead 100, an introductionport 101 for introducing a material-based gas comprising a gas whosemolecular formula includes Si and/or C (hereinafter simply referred toas “material-based gas”), an introduction port 102 for introducing anon-Si non-C-based gas comprising a gas whose molecular formula excludesSi and C (hereinafter simply referred to as “non-Si non-C-based gas”), amaterial-based gas introducing channel 103, a non-Si non-C-based gasintroducing channel 104, a thermal catalysis body 105, an electric powersource 106 for heating the thermal catalysis body, a plasma space 107, anonplanar electrode 108 for plasma generation, a radio frequency powersupply 109 for plasma generation, material-based gas effusion ports 110,non-Si non-C-based gas effusion ports 111, a substrate 112 on which afilm is deposited, a heater 113 for heating the substrate, and a vacuumpump 114 for exhausting gas.

[0038]FIG. 2 illustrates a film forming apparatus for implementing theCat-PECVD method according to a second embodiment of the presentinvention. In this film forming apparatus, the showerhead comprises afirst showerhead provided separately from a nonplanar electrode and asecond showerhead formed integrally with a nonplanar electrode.

[0039] In the drawing, there are shown a first showerhead 200, anintroduction port 201 for introducing material-based gas comprising agas whose molecular formula includes Si and/or C, an introduction port202 for introducing non-Si non-C-based gas, a material-based gasintroducing channel 203, a non-Si non-C-based gas introducing channel204, a thermal catalysis body 205, an electric power source 206 forheating the thermal catalysis body, a plasma space 207, a nonplanarelectrode 208 for plasma generation formed integrally with a secondshowerhead 216, a radio frequency power supply 209 for plasmageneration, material-based gas effusion ports 210, non-Si non-C-basedgas effusion ports 211, a substrate 212 on which a film is deposited, aheater 213 for heating the substrate, a vacuum pump 214 for exhaustinggas, and a radiation shielding member 215.

[0040]FIG. 3 illustrates a film forming apparatus for implementing theCat-PECVD method according to a third embodiment of the presentinvention. In this film forming apparatus, the radiation shieldingarrangement in the showerhead is varied from that in the firstembodiment.

[0041] In the drawing, there are shown a showerhead 300 in whichnonlinear gas effusion paths are employed for realizing a radiationshielding structure, an introduction port 301 for introducingmaterial-based gas, an introduction port 302 for introducing non-Sinon-C-based gas, a material-based gas introducing channel 303, a non-Sinon-C-based gas introducing channel 304, a thermal catalysis body 305,an electric power source 306 for heating the thermal catalysis body, aplasma space 307, a nonplanar electrode 308 for plasma generation, aradio frequency power supply 309 for plasma generation, material-basedgas effusion ports 310, non-Si non-C-based gas effusion ports 311, asubstrate 312 on which a film is deposited, a heater 313 for heating thesubstrate, and a vacuum pump 314 for exhausting gas.

[0042] The vacuum pump 314 for exhausting gas is preferably a dry-typevacuum pump such as a turbo-molecular pump so as to prevent impuritiesfrom getting into the film from the exhaust system. Here, the ultimatevacuum is at least 1E-3Pa, and more preferably, it is 1E-4Pa or less.The pressure during the film formation is in the range of about 10-1000Pa. The temperature for heating the substrate 312 by the heater 313 isin the range of 100-400.degree.C., and more preferably, it is in therange of 150-300.degree.C.

[0043] Hereinafter, description of portions that are in common amongEmbodiments 1, 2, and 3 will be represented by the description given toEmbodiment 1, and portions that differ from one another will bedescribed according to the respective Embodiments.

[0044] <Geometry of Electrode>

[0045] An explanation is now given to the nonplanar electrode 108 forplasma generation. A specific geometry of the nonplanar electrode 108may be the kind shown in FIG. 6, which comprises a plurality ofbar-shaped electrodes juxtaposed to one another and is generally calledan “antenna-style” or a “ladder-style”, or may be a spoke antenna-styleshown in FIG. 7.

[0046] In general, the relationship between frequency f and wavelength λof the radio frequency power supply 109 is given in plasma as λ=v/f.Here, v is the velocity of propagation of electromagnetic waves inplasma, which is smaller than speed c (speed of light) ofelectromagnetic waves in vacuum. Accordingly, λ is smaller than c/f.

[0047] To discuss a length L of one side of a rectangular electrode as atypical size of the electrode 108 for plasma generation, when λ>>L,electromagnetic interference (standing wave) does not arise, and hence ahomogeneous plasma is formed. As a result, films with uniform thicknessand homogeneous quality can be formed. For example, when f=13.5 MHz, λis about 22 m at the maximum. This explains that the influence ofelectromagnetic interference is insignificant in the case of a 1 squaremeter-size electrode 108 for plasma generation. However, when λ/4 comesin the vicinity of L or below as the frequency f of the radio frequencypower supply 109 rises, the influence of electromagnetic interferencebecomes too great to be negligible. For example, when f=60 MHz, λ/4 is1.25 m at the maximum. A simple, planar, 1 square meter electrode forplasma generation therefore incurs the influence of electromagneticinterference. In such a case, even distribution of electromagnetic fieldcannot be expected, which means uniform plasma generation cannot beexpected. For this reason, generally, an antenna-style, a ladder-styleor spoke antenna-style nonplanar electrode 108 is employed instead ofsuch a planar electrode for plasma generation for regions where thefrequency of the radio frequency power supply 109 is about 40 MHz ormore that is in the VHF band or higher, thereby to accomplish uniformplasma generation. This can be utilized in the Cat-PECVD method of thepresent invention.

[0048] <Method for Supplying Electric Power>

[0049] Method for supplying electric power are now described. In caseswhere an antenna-style electrode is employed as the nonplanar electrode108 for plasma generation, a radio frequency power from the radiofrequency power supply 109 may be distributed among the plurality ofbar-shaped electrodes, or a plurality of such radio frequency powersupplies 109 may be provided for the respective bar-shaped electrodes.Additionally, in order to prevent unwanted interference from occurring,it is preferable that the radio frequency powers differ in phase atleast between adjacent electrodes.

[0050] <Method for Supplying Radio Frequency Power>

[0051] Another method for further facilitating the formation oflarge-area films with uniform thickness and homogeneous quality is amultiple application of radio frequency power in which a plurality ofradio frequency powers having different frequencies are applied to theelectrode 108 for plasma generation so that a plurality of plasmashaving different spatial density distributions are overlapped oneanother. Still another method is to temporally vary and modulate thefrequency of the radio frequency power so as to vary the spatial densitydistribution of the plasma for taking the time average thereof therebyconsequently accomplishing uniform film formation. Incidentally, byintermittently supplying radio frequency power to the electrode 108 forplasma generation by means of, for example, pulse-modulating the plasma,formation and growth of powder can be suppressed as compared with thecase of continuous plasma generation, which is effective in some casesfor improvement of the film quality.

[0052] <Relationship Between Showerhead and Electrode>

[0053] To classify broadly, there are three types of relationshipsbetween the showerhead 100 and the nonplanar electrode 108 for plasmageneration.

[0054] (1) The first type is the simplest type as shown in FIG. 1 inwhich the showerhead 100 and the electrode 108 for plasma generation areseparately provided. In this arrangement, gas effusion and plasmageneration can each be controlled to be uniform independently by theshowerhead 100 and nonplanar electrode 108, respectively. Designing ofthe apparatus and handling thereof are therefore relatively easy.However, since the material-based gas needs to flow from the showerhead100 toward the substrate 112 through clearances in the nonplanarelectrode 108, unevenness in gas flow may arise depending on thegeometry and the area of the nonplanar electrode 108. Therefore, theremay be cases where this type of relationship is not necessarilypreferable for large-area film formation with uniform film thickness andhomogeneous film quality.

[0055] (2) The second type is the one shown in FIG. 2 in which theapparatus is arranged to comprise the first showerhead 200 which isseparately provided from the nonplanar electrode 208, and the secondshowerhead 216 which is integrally formed with the nonplanar electrode208, in which the second showerhead 216 integrally formed with thenonplanar electrode 208 is arranged to effuse the material-based gastherefrom. This arrangement allows the material-based gas to beadequately supplied to portions under the shade of the electrode 108 forplasma generation, thereby mitigating the aforementioned problem.

[0056] In this case, when the first showerhead 200 is substituted withthe showerhead 100 shown in FIG. 1 so that the two showerheadssimultaneously effuse the material-based gas (not shown in thedrawings), deposition can be accomplished with more uniformity inthickness and homogeneity in quality.

[0057] Additionally, it is also possible in some events to reverse theabove described relationship between the material-based gas and thenon-Si non-C-based gas so that the material-based gas is effused fromthe first showerhead 200 and the non-Si non-C-based gas is effused fromthe second showerhead 216. By this arrangement, in cases where H₂ gas isused as the non-Si non-C-based gas, it becomes easier to controlgeneration of active hydrogen gas to be uniform, and hence, for example,it becomes easier to uniformize the distribution of crystallizationratio in crystalline Si films.

[0058] (3) Finally, the third type is one which is not shown in thedrawings, in which the first showerhead 200 is eliminated in the secondtype arrangement, and the second showerhead 216 is arranged to becomplete with the functions to effuse the material-based gas and thenon-Si non-C-based gas separately from each other, and to accommodate athermal catalysis body so as to be disposed in a channel for introducingthe non-Si non-C-based gas. In this type, while the electrode for plasmageneration may have a complicated structure, since the gas effusionports are provided only in the electrode for plasma generation, filmdeposition can be performed simultaneously on both sides with theelectrode for plasma generation interposed in between. This is anadvantage leading to great improvement in productivity of the apparatus.

[0059] <Frequency of Radio Frequency Power Supply>

[0060] The Cat-PECVD method and film forming apparatus according to thepresent invention are characterized in that the electrode 108 for plasmageneration is connected to the radio frequency power supply 109, and thefrequency of the radio frequency power supply 109 is 13.56 MHz or more.The advantageous effect of the present invention, in other words, thelarge-area film formation with uniform film thickness and homogeneousfilm quality, is significantly exhibited particularly in a highfrequency range of 27 MHz or more, which is within or higher thanso-called VHF band. That is, in the cases of conventional planarelectrodes for plasma generation, the frequency at which films about 1square meter in size can be formed in large area with uniform thicknessand homogeneous quality without much difficulty is not more than about27 MHz, and such film formation is not necessarily easy at frequencieshigher than this level. On the other hand, large area film formation canbe accomplished with far more excellent properties even at a highfrequency range of more than 27 MHz by the present invention. The highfrequencies in the VHF band may be arbitrarily selected as continuousquantity, and preferably an optimal frequency is selected according tothe size and configuration of the electrode. However, in normal cases,it will be sufficient to use the frequencies that are frequently used inthe industry such as 40 MHz, 60 MHz, 80 MHz, and 100 MHz. Here, thehigher the frequency of the radio frequency power supply 109 is, thehigher the electron concentration in the plasma is. The rate ofdecomposition and activation of the material-based gas is increasedaccordingly, thereby increasing the deposition rate. In cases where H₂gas is used as the non-Si non-C-based gas, since the ratio of atomichydrogen to be generated is increased, more significant crystallizationpromoting effect can be obtained. Accordingly, crystalline Si films canbe obtained even in a condition for high-speed deposition. Moreover,according to the present invention, activation of the non-Si non-C-basedgas can be accelerated by use of the thermal catalysis body.Accordingly, when H₂ gas is employed as the non-Si non-C-based gas, thecrystallization promoting effect is enhanced in addition to theaforementioned effect of the VHF band frequency itself. Thus,crystalline Si films with high quality can be obtained even in acondition for higher-speed deposition.

[0061] Incidentally, there is no necessity to limit the frequency of theradio frequency power supply to those within the VHF band up to about100 MHz, but frequencies in the higher UHF band and those in themicrowave range can also be used.

[0062] When the radiation shielding member 115,215 is used, theradiation shielding member 115,215 is preferably be provided with agreat number of holes for passing gas so as not to block the flow ofgas.

[0063] <Radiation Shielding Structure>

[0064] In the Cat-PECVD method and the film forming apparatus accordingto the present invention, the showerhead 100 preferably has a structurethat prevents radiation emitted from the thermal catalysis body 105 frombeing directly delivered to the substrate 112.

[0065] In this embodiment, such a radiation shielding structure isembodied by the use of the radiation-shielding member 115, 215 shown inFIGS. 1, 2, or by arranging the gas effusion ports of the showerhead 300in a nonlinear manner as shown in FIG. 3. By this structure, radiationfrom the thermal catalysis body 105 is shielded and prevented from beingdirectly delivered to the surface of the substrate 112. As a result,unfavorable temperature increase in the substrate 112 can be suppressed,thereby the film quality can be controlled to be more stable.

[0066] <Method for Gas Effusion>

[0067] The distance d1 between the gas effusion ports 110 for thematerial-based gas and the gas effusion ports 111 for the non-Sinon-C-based gas of the showerhead 100 that are adjacent to each other ispreferably the distance d2 between the showerhead 100 and the substrate112 or less.

[0068] This arrangement further facilitates homogenization of the mixedgases, and makes it easier to accomplish uniformization of the filmthickness and homogenization of the film quality over a large area. Inorder to further promote uniformization of the film thickness andhomogenization of the film quality over a large area, the arrangementmay be such that the material-based gas and the heated non-Sinon-C-based gas are mixed together while they are passing through theshowerhead 100.

[0069] As described so far, by the combination of the nonplanerelectrode 108 for plasma generation with the showerhead 100, large-areafilms of 1 square meter in size can be formed with uniform thickness andhomogeneous quality with comparative ease, which is not necessarily easyfor the conventional combination of a planar electrode for plasmageneration with a showerhead to accomplish. Namely, the film thicknessdistribution can be controlled to be within a fluctuation range of ±15%or less, the filmquality distribution, for example, thecrystallizationratio can be controlled to be within a fluctuation range of ±15% orless, and as Si thin-film solar cell property distribution, theconversion efficiency can be controlled to be within a fluctuation rangeof ±10% or less.

[0070] <Substrate Bias>

[0071] When a direct current power source or a radio frequency powersupply that operates at a frequency range lower than that of the radiofrequency power supply 109 for plasma generation is connected to theelectrode on the side of the substrate so that a bias voltage can beapplied to the substrate 112, the degree of the ion bombardment on thesubstrate 112 can be controlled. This is effective for cleaning thesubstrate surface before film deposition and controlling the filmquality with properly controlled ion bombardment during film deposition.

[0072] <Thermal Catalysis Body (Catalyzer)>

[0073] The thermal catalysis body 105 comprises a metal material atleast in its substrate. The metal material preferably comprises, as amain component thereof, at least one high-melting point metal selectedfrom the group consisting of Ta, W, Re, Os, Ir, Nb, Mo, Ru, and Pt. Forthe thermal catalysis body 105, while a metal material formed into awire shape described above is usually employed, the form is not limitedto such a wire shape but may be the form of a plate or a mesh.Incidentally, in the event where impurities unfavorable for filmdeposition are included in the metal material for the thermal catalysisbody, an effective measure to reduce the impurities is to preheat thethermal catalysis body 105 for several minutes or more at a temperatureequal to or higher than the temperature during a film deposition beforeit is used for the film deposition.

[0074] <Power Source for Heating Thermal Catalysis Body>

[0075] For the power source 106 for heating the thermal catalysis body105, normally a direct-current power source is conveniently used.However, using an alternating current power source causes noinconvenience. In addition, when a direct-current power source is used,as will be later described, the arrangement may be such that directcurrent is supplied to the thermal catalysis body 105 in a pulsivemanner so as to control the degree of heating or decomposition and.activation of the non-Si non-C-based gas.

[0076] <Activation of Non-Si Non-C-Based Gas>

[0077] The non-Si non-C-based gas is heated by the thermal catalysisbody 105 and directed toward the plasma space 107, while a part of it isdecomposed and activated by the thermal catalysis body 105, the degreeof which is proportional to the temperature of the thermal catalysisbody. To take H₂ gas as an example, while it depends on the pressure,generation of atomic hydrogen due to the decomposition.reaction becomessignificant around the point at which the temperature of the thermalcatalysis body exceeds approximately 1000.degree.C. This atomic hydrogensignificantly contributes to acceleration of crystallization of Sifilms. Additionally, even when the temperature of the thermal catalysisbody is approximately 1000.degree.C. or below at which generation ofatomic hydrogen is not too significant, and therefore the effect ofaccelerating crystallization can not be expected to be significant,since the use of the thermal catalysis body brings about a gas heatingeffect as a secondary effect, the reaction to produce higher-ordersilane species can be suppressed. Accordingly, film deposition evenunder such a thermal condition is still effective for formation ofhigh-quality hydrogenated amorphous silicon films. However, in order toobtain the above described effect, the temperature of the thermalcatalysis body is preferably at least 100.degree.C. or more, or morepreferably, 200.degree.C.or more. At temperatures of 200.degree.C. ormore, the gas heating effect can be more significant. The maximumtemperature is preferably 2000.degree.C. or below, or more preferably,1900.degree.C. or below. This is because problems such as release ofgaseous impurities from the thermal catalysis body and parts around itand evaporation of the material of the thermal catalysis body itself mayarise at temperatures above 1900.degree.C.

[0078] <Method for Controlling Activation Degree >

[0079] Apart from the control by means of the temperature of the thermalcatalysis body described above, control of the degree of heating ordecomposition and activation of the non-Si non-C-based gas, which istypically represented by H₂ mentioned above, can be accomplished by thefollowing five methods:

[0080] (1) The first method is to control the surface area of thethermal catalysis body 105. By this method, the degree of heating ordecomposition and activation of the non-Si non-C-based gas can becontrolled without decrease in temperature of the thermal catalysis bodyso that it can be maintained at a temperature higher than a certainlevel. For example, when a linearly shaped component is used for thethermal catalysis body 105, the surface area of the thermal catalysisbody 105 can be controlled by the choice of length and diameter. Becausechanging the length or the diameter of the thermal catalysis body 105during the use of the apparatus is practically difficult, it may bearranged such that a plurality of thermal catalysis bodies 105 each ofwhich can be heated independently are provided (not shown in thedrawings) and the number of the thermal catalysis bodies to be heated isdetermined according to the need. In such a manner, the degree ofheating or decomposition and activation of the non-Si non-C-based gascan be varied step-by-step.

[0081] (2) The second method is to perform heating of the thermalcatalysis body 105 intermittently or periodically. Specifically, theelectric power of the power source 106 for heating is givenintermittently in a pulsed manner or a low frequency AC power source isused so that the heating of the thermal catalysis body can be effectedperiodically. By this method, durations of the reaction between thenon-Si non-C-based gas and the thermal catalysis body 105 per unit timecan be continuously controlled, and hence the degree of heating ordecomposition and activation of the non-Si non-C-based gas can becontrolled continuously.

[0082] (3) The third method is to allow the distance between the thermalcatalysis body 105 and the gas effusion ports 111 for the non-Sinon-C-based gas of the showerhead 100 to be variable. Since decomposedand activated non-Si non-C-based gas has a duration of life, the degreeof decomposition and activation of the non-Si non-C-based gas effusedfrom the gas effusion ports 111 for the non-Si non-C-based gas can bedecreased by extending the distance, and increased by reducing thedistance.

[0083] (4) The fourth method is adjustment by designing the borediameters of the non-Si non-C-based gas effusion ports 111 and those ofthe material-based gas effusion ports 110 differently from each other,or by designing the total number of the non-Si non-C-based gas effusionports 111 and that of the material-based gas effusion ports 110differently from each other. By reducing the bore diameters of thenon-Si non-C-based gas effusion ports 111 or decreasing the total numberof the same, the amount of heated or decomposed and activated non-Sinon-C-based gas effused into the plasma space 107 can be reduced, and byexpanding the bore diameters of the non-Si non-C-based gas effusionports 111 or increasing the total number of the same, the amount ofheated or decomposed and activated non-Si non-C-based gas effused intothe plasma space 107 can be increased.

[0084] (5) The fifth method is to add a channel (not shown in thedrawings) for introducing the non-Si non-C-based gas which is notprovided with a thermal catalysis body, thereby to independently controleach of the amount of non-Si non-C-based gas flow passing through thethermal catalysis body and the amount of non-Si non-C-based gas flow notpassing through the thermal catalysis body. By this arrangement, thenon-Si non-C-based gas that is heated or decomposed and activated andthe non-Si non-C-based gas that is not heated can be blended at anarbitrary gas flow ratio, and hence the concentration of the heated ordecomposed and activated non-Si non-C-based gas to be effused from theshowerhead 100 toward the plasma space 107 can be varied continuously.Meanwhile, the gas-introducing channel for non-Si non-C-based gas to benot heated may be merged with the material-based gas introducing channel103.

[0085] <Material for Gas Channel>

[0086] It is preferable that at least a part of a surface of at leastany one of an inner wall of a gas pipe, an inner wall of the showerheadand the radiation shielding member in the non-Si non-C-based gasintroducing channel 104 comprises a material including at least one ofthe group consisting of Ni, Pd and Pt. Since these metal elements servea catalytic function to promote dissociation of gas molecules such asH₂, it is possible to reduce the possibility of recombination andinactivation of decomposed and activated non-Si non-C-base gas on thesurfaces of the above-mentioned members.

[0087] <Heating of Material-Based Gas>

[0088] The material-based gas introducing channel 103 is preferablyprovided with a thermal catalysis body (made of the same material asthat of the thermal catalysis body 105) in order to promote the gasheating effect. However, in order not to cause the material-based gas tobe decomposed due to the thermal catalysis body, the temperature of thethermal catalysis body should be controlled to be below the temperatureat which the material-based gas decomposes. In cases where SiH₄ is usedas the material-based gas, the temperature is so controlled as to be500.degree.C. or below, or desirably, 400.degree.C. or below.

[0089] There is another method for promoting the gas heating effect,which is to heat the internal wall surface of the film depositionchamber. Specifically, a heater (not shown in the drawings) is providedwithin the film deposition chamber so as to accomplish the heating ofthe internal wall surface of the film deposition chamber. In this case,when the material-based gas includes a gas containing Si, thetemperature of the heater mentioned above is so controlled as to be500.degree.C. or below, or desirably, 400.degree.C. or below.

[0090] <Doping Gas Introducing Method>

[0091] When a doping gas is fed, it can be introduced into thematerial-based gas introducing channel 103 or the non-Si non-C-based gasintroducing channel 104. In this case, B₂H₆ and the like may be used asp-type doping gas, and PH₃ and the like may be used as n-type dopinggas.

[0092] <Electric Circuit>

[0093] In the circuit of the power source 106 for heating thermalcatalysis body, a pass condenser or capacitor (not shown) is preferablyprovided as a method for blocking radio frequency. By this method, radiofrequency components from the radio frequency power supply can beprevented from entering, and stable film formation can therefore befurther ensured.

[0094] <Substrate Geometry>

[0095] The geometry of the substrate 112 may be planar for devices suchas solar cells, and nonplanar shapes such as cylindrical shapes may beemployed for devices such as photosensitive drums.

[0096] <CVD Apparatus>

[0097] The CVD apparatus for implementing the Cat-PECVD method accordingto the present invention is an apparatus, as shown in FIG. 8, whichcomprises a plurality of vacuum chambers 801 to 810 including at leastone film deposition chamber capable of implementing the aforementionedmethod.

[0098] Here, the plurality of vacuum chambers preferably include atleast film deposition chambers for forming p-type films 803, 806, filmdepositionchambers for forming i-type films 804, 807, and filmdeposition chambers for forming n-type films 805, 808, wherein at leastthe film deposition chamber for forming i-type films 807 and/or 804 isfilm deposition chamber capable of implementing the Cat-PECVD method.

[0099] In addition, it is preferable that at least one of the pluralityof the vacuum chambers is a film deposition chamber capable ofimplementing the Cat-CVD method. By this arrangement, for example,hydrogenated amorphous silicon films can be formed at high depositionrate with high quality by the Cat-CVD method, which enables hydrogenatedamorphous silicon films to be employed, for example, for photoactivelayers in the top cells of tandem solar cells, thereby expanding thepossibility of combinations in forming multiple layer films. It has beenknown that the hydrogen concentrations of hydrogenated amorphous siliconfilms formed by the Cat-CVD method can be lower than those of thehydrogenated amorphous silicon films formed by the PECVD method.Therefore, further improved light absorption property and smalleroptical band gap can be achieved. Also advantageously, deterioration dueto light, which is the long time problem in hydrogenated amorphoussilicon, can be reduced to a low level.

[0100] The plurality of vacuum chambers preferably include at least onefilm deposition chamber capable of implementing the PECVD method. Thisallows film deposition to be effected on the surfaces of films that aresusceptible to reduction by atomic hydrogen such as transparentconductive oxide films in a condition in which the reduction reaction issuppressed as much as possible, so that the possibility of combinationsin forming multiple layer films can be expanded.

[0101] In addition, the plurality of vacuum chambers preferably includeat least a pre-chamber 801 so as not to expose the film depositionchambers to the ambient air, and the plurality of vacuum chamberspreferably include the pre-chamber 801 and subsequent chambers 809 and810 for improvement of productivity. Furthermore, the plurality ofvacuum chambers preferably include a heating chamber 802 also forimprovement of productivity.

[0102] The plurality of vacuum chambers 801 to 810 may be arranged suchthat the plurality of vacuum chambers are linearly connected to oneanother in a row, or the plurality of vacuum chambers may be arranged soas to be connected to a core chamber present at least one in number,thereby to form a star-like configuration.

[0103] When the film deposition is performed in a horizontal-styledeposition chamber, it may be performed in a deposit-down style in whichthe deposition species is deposited on the substrate 112 from thegravitationally higher side with respect to the substrate 112. To thecontrary, the film deposition may be performed in a deposit-up style inwhich the deposition species is deposited on the substrate 112 from thegravitationally lower side with respect to the substrate 112. The formerstyle has the advantage that, because of good adhesion between thesubstrate 112 and the heater 113, it is easy to achieve even thermaldistribution all over the substrate. However, the former style also hasthe problem of susceptibility to deposition of foreign objects such aspowder falling thereon. On the other hand, the latter style can reducethe degree of deposition of foreign objects such as powder, but has theproblem that it is difficult to achieve even thermal distribution overthe substrate due to bending of the substrate or the like. The selectionbetween the former and the latter may be made by taking their advantagesand disadvantages into consideration.

[0104] A method for relatively successfully combining the features ofthe both styles is to employ a vertical deposition chamber. By utilizingthe vertical chamber structure, it is possible to realize a structurethat is less susceptible to deposition of foreign objects such as powderthan the horizontal deposit-down style and allows even thermaldistribution all over the substrate to be achieved more easily than inthe horizontal deposit-up style.

[0105] <Film>

[0106] By the Cat-PECVD method according to the present invention, it ispossible to form high-quality films at high deposition rate over largearea with high uniformity in both thickness and quality. However, morespecifically, the advantageous-effect of the present invention isexerted particularly significantly on Si-based films and C-based filmsas described as follows:

[0107] (1) A first example is a Si-based film formed by the use of amaterial-based gas which comprises a gas whose molecular formulaincludes Si and excludes a gas whose molecular formula includes C, and anon-Si non-C-based gas which comprises H₂. Specifically, for example, byusing SiH₄ as the material-based gas and H₂ as the non-Si non-C-basedgas, because of the aforementioned reason, high quality hydrogenatedamorphous silicon films and crystalline silicon films includingmicro-crystalline, mono-crystalline and poly-crystalline silicons filmscan be formed over large area at high deposition rate with highuniformity in film thickness and quality.

[0108] (2) A second example is a Si-C-based film formed by the use of amaterial-based gas comprising a gas whose molecular formula includes Siand a gas whose molecular formula includes C, and a non-Si non-C-basedgas comprising H₂ Specifically, for example, by using SiH₄ and CH₄ asthe material-based gas and H₂ as the non-Si non-C-based gas, because ofthe aforementioned reason, high-quality hydrogenated amorphous siliconcarbide films and crystalline silicon carbide films can be formed overlarge area at high deposition rate with high uniformity in filmthickness and quality.

[0109] (3) A third example is a Si-N-based film formed by the use of amaterial-based gas comprising a gas whose molecular formula includes Si,a non-Si non-C-based gas comprising H₂, and a gas whose molecularformula includes N which is included at least in either of thematerial-based gas and non-Si non-C-based gas. Specifically, forexample, by using SiH₄ as the material-based gas, H₂ as the non-Sinon-C-based gas, and NH₃ as the gas comprising N, because of theaforementioned reason, high quality hydrogenated amorphous siliconnitride films and crystalline silicon nitride films can be formed overlarge area at high deposition rate with high uniformity in filmthickness and quality.

[0110] (4) A fourth example is a Si-O-based film formed by the use of amaterial-based gas comprising a gas whose molecular formula includes Siand a non-Si non-C-based gas comprising O₂. Specifically, for example,by using SiH₄ and, if necessary, H₂ as the material-based gas, and O₂and, if necessary, He and Ar as the non-Si non-C-based gas, because ofthe aforementioned reason, high-quality amorphous silicon oxide filmsand crystalline silicon oxide films can be formed over large area athigh deposition rate with high uniformity in film thickness and quality.

[0111] (5) A fifth example is a Si-Ge-based film formed by the use of amaterial-based gas comprising a gas whose molecular formula includes Siand a gas whose molecular formula includes Ge, and a non-Si non-C-basedgas comprising H₂. Specifically, for example, by using SiH₄ and GeH₄ asthe material-based gas, and H₂ as the non-Si non-C-based gas, because ofthe aforementioned reason, high quality hydrogenated amorphous silicongermanium films and crystalline silicon germanium films can be formedover large area at high deposition rate with high uniformity in filmthickness and quality.

[0112] (6) A sixth example is a C-based film formed by the use of amaterial-based gas comprising a gas whose molecular formula includes Cand a non-Si non-C-based gas comprising H₂. Specifically, for example,by using CH₄ and, if necessary, small amount of O₂ as the material-basedgas, and H₂ as the non-Si non-C-based gas, because of the aforementionedreason, high-quality amorphous carbon films and crystalline carbon filmscan be formed over large area at high deposition rate with highuniformity in film thickness and quality. Namely, diamond films anddiamond-like carbon films can be formed.

[0113] <Device>

[0114] By the use of the films formed by the Cat-PECVD method accordingto the present invention, it is possible to manufacture the devicesrecited below with high performance and at low cost.

[0115] (1) A first example of device is a photoelectric conversiondevice, which can be manufactured with high performance characteristicsat high speed, in other words, at low cost, by the use of a film formedby the Cat-PECVD method according to the present invention for aphotoactive layer. In particular, the high-deposition rate, high-qualityand large-area film formation characteristics of the Cat-PECVD methodaccording to the present invention can be exhibited sufficiently insolar cells, the typical of photoelectric conversion devices. Thin-filmsolar cells with high efficiency can therefore be manufactured at lowcost. It is needless to add that the same effect can be achieved indevices other than solar cells including photodiodes, image sensors andX-ray panels that have a photoelectric conversion function.

[0116] (2) A second example of device is a photoreceptor device, whichcan be manufactured with high performance characteristics at high speed,in other words, at low cost, by the use of a film formed by theCat-PECVD method according to the present invention for a photoreceptorlayer. In particular, the film is effectively used as a silicon-basedfilm in photosensitive drums.

[0117] (3) A third example of device is a display device, which can bemanufactured with high properties at high speed, in other words, at lowcost, by the use of a film formed by the CatPECVD method according tothe present invention for a driving layer. In particular, the film iseffectively used as an amorphous silicon film or a polycrystallinesilicon film in TFTS (thin film transistors). The same effect can beachieved in devices other than TFTs, including image sensors and X-raypanels that have a display function.

1. A Cat-PECVD method for depositing a film on a substrate comprisingthe steps of: introducing a non-Si non-C-based gas comprising a gaswhose molecular formula excludes Si and C into a first introductionchannel; heating the non-Si non-C-based gas introduced into the firstintroduction channel by a thermal catalysis body; introducing amaterial-based gas comprising a gas whose molecular formula includes Siand/or C into a second introduction channel; introducing thematerial-based gas and the non-Si non-Cbased gas heated by the thermalcatalysis body separately from each other into a film deposition spacethrough a showerhead having a plurality of gas effusion ports; andforming a plasma space in the film deposition space by means of anonplanar electrode connected to a radio frequency power supply, therebydepositing a film on the substrate.
 2. The Cat-PECVD method according toclaim 1, wherein the material-based gas and the heated non-Sinon-C-based gas are blended together as they pass through theshowerhead.
 3. The Cat-PECVD method according to claim 1, wherein a partof the heated non-Si non-C-based gas is decomposed and activated anddirected into the plasma space.
 4. The Cat-PECVD method according toclaim 1, wherein a doping gas is introduced into the second introductionchannel or the first introduction channel.
 5. A film forming apparatusfor implementing a Cat-PECVD method for depositing a film on asubstrate, the apparatus comprising: a first introduction channel forintroducing a non-Si non-C-based gas comprising a gas whose molecularformula excludes Si and C; a thermal catalysis body provided in thefirst introduction channel for heating the non-Si non-C-based gasintroduced thereinto; a second introduction channel for introducing amaterial-based gas comprising a gas whose molecular formula includes Siand/or C; a showerhead having a plurality of gas effusion ports fordirecting the material-based gas and the non-Si non-C-based gas heatedby the thermal catalysis body into a film deposition space separatelyfrom each other; and a nonplanar electrode connected to a radiofrequency power supply for forming a plasma space in the film depositionspace.
 6. The film forming apparatus according to claim 5, wherein thenonplanar electrode comprises a plurality of bar-shaped electrodesjuxtaposed to one another.
 7. The film forming apparatus according toclaim 6, wherein a radio frequency power from the radio frequency powersupply is distributed among the plurality of bar-shaped electrodes. 8.The film forming apparatus according to claim 6, wherein high frequencypowers supplied to the plurality of bar-shaped electrodes differ inphase at least between adjacent electrodes.
 9. The film formingapparatus according to claim 6, wherein the plurality of bar-shapedelectrodes are each connected to a separate radio frequency powersupply.
 10. The film forming apparatus according to claim 5, wherein thenonplanar electrode is an antenna electrode in the form of a spoke. 11.The film forming apparatus according to claim 5, wherein a plurality ofradio frequency powers each having a different frequency are supplied tothe nonplanar electrode.
 12. The film forming apparatus according toclaim 5, wherein the frequency of the radio frequency power supplied tothe nonplanar electrode is temporally varied and modulated.
 13. The filmforming apparatus according to claim 5, wherein a radio frequency poweris intermittently supplied to the nonplanar electrode.
 14. The filmforming apparatus according to claim 5, wherein the showerhead isprovided separately from the nonplanar electrode.
 15. The.film formingapparatus according to claim 5, wherein the showerhead is formedintegrally with the nonplanar electrode.
 16. The film forming apparatusaccording to claim 5, wherein there are a plurality of the showerheads,a part of which being separated from the nonplanar electrode and anotherpart of which being formed integrally with the nonplanar electrode. 17.The film forming apparatus according to claim 16, wherein the part ofthe showerheads separated from the nonplanar electrode effuses thematerial-based gas therefrom, and the part of the showerheads formedintegrally with the nonplanar electrode effuses the non-Si non-C-basedgas therefrom.
 18. The film forming apparatus according to claim 16,wherein the part of the showerheads separated from the nonplanarelectrode effuses the non-Si non-C-based gas therefrom, and the part ofthe showerheads formed integrally with the nonplanar electrode effusesthe material-based gas therefrom.
 19. The film forming apparatusaccording to claim 5, wherein the radio frequency power supply has afrequency of 13 MHz or more.
 20. The film forming apparatus according toclaim 5, wherein the radio frequency power supply has a frequency of 27MHz or more.
 21. The film forming apparatus according to claim 5,wherein the radio frequency power supply has a frequency of 40 MHz ormore.
 22. The film forming apparatus according to claim 5, whereinthe-radio frequency power supply has a frequency of 60 MHz or more. 23.The film forming apparatus according to claim 5, wherein the radiofrequency power supply has a frequency of 80 MHz or more.
 24. The filmforming apparatus according to claim 5, wherein the radio frequencypower supply has a frequency of 100 MHz or more.
 25. The film formingapparatus according to claim 5, wherein the first introduction channelprovided with the thermal catalysis body includes a radiation shieldingarrangement for preventing radiation emitted from the thermal catalysisbody from being delivered directly to the substrate for film depositiondisposed in the film deposition space.
 26. The film forming apparatusaccording to claim 25, wherein the radiation shielding arrangement isaccomplished by a nonlinear arrangement of the gas effusion ports of theshowerhead.
 27. The film forming apparatus according to claim 25,wherein the radiation shielding arrangement is accomplished by providinga radiation shielding member between the thermal catalysis body and thegas effusion ports of the showerhead.
 28. The film forming apparatusaccording to claim 25, wherein the radiation shielding member has amultiplicity of holes that serve as gas flow pathways.
 29. The filmforming apparatus according to claim 5, wherein the distance between gaseffusion ports for the material based gas and gas effusion ports for thenon-Si non-C-based gas of the showerhead that are adjacent to each otheris the distance between the nonplanar electrode and the substrate orless.
 30. The film forming apparatus according to claim 5, wherein adirect-current power source or a radio frequency power supply with afrequency lower than that of the radio frequency power supply for plasmageneration is connected to a holder for holding the substrate so as toapply a bias voltage to the substrate.
 31. The film forming apparatusaccording to claim 5, wherein at least a surface of the thermalcatalysis body comprises a metal material comprising, as a maincomponent thereof, at least one element selected from the groupconsisting of Ta, W, Re, Os, Ir, Nb, Mo, Ru, and Pt.
 32. The filmforming apparatus according to claim 31, wherein the thermal catalysisbody is in the form of a wire.
 33. The film forming apparatus accordingto claim 31, wherein the thermal catalysis body is in the form of aplate or a mesh.
 34. The film forming apparatus according to claim 31,wherein the thermal catalysis body is preheated for several minutes ormore at a temperature equal to or above a temperature at the time offilm deposition.
 35. The film forming apparatus according to claim 31,wherein the electric power source for heating the thermal catalysis bodyis a direct current power source.
 36. The film forming apparatusaccording to claim 31, wherein the electric power source for heating thethermal catalysis body is an alternating current power source.
 37. Thefilm forming apparatus according to claim 5, wherein the temperature ofthe thermal catalysis body is 100.degree.C. or more and 2000.degree.C.or less.
 38. The film forming apparatus according to claim 5, whereinthe temperature of the thermal catalysis body is 200.degree.C. or moreand 1900.degree.C. or less.
 39. The film forming apparatus according toclaim 5, wherein there are provided a plurality of the thermal catalysisbodies, which are each heated independently from one another.
 40. Thefilm forming apparatus according to claim 5, wherein the thermalcatalysis body is heated intermittently or periodically.
 41. The filmforming apparatus according to claim 5, wherein the distance between thethermal catalysis body and the gas effusion ports of the showerhead isvariable.
 42. The film forming apparatus according to claim 5, whereinthe bore diameters of the gas effusion ports are different between gaseffusion ports for the material-based gas and gas effusion ports for thenon-Si non-C-based gas.
 43. The film forming apparatus according toclaim 5, wherein the number of the gas effusion ports for thematerial-based gas and the number of the gas effusion ports for thenon-Si non-C-based gas are different from each other.
 44. The filmforming apparatus according to claim 5, wherein there are a plurality ofthe introduction channels for introducing the non-Si non-C-based gas,and the non-Si non-C-based gas that passes through at least one of theplurality of introduction channels is directed toward the plasma spacewithout being heated by the thermal catalysis body.
 45. The film formingapparatus according to claim 44, wherein the introduction channel forintroducing the non-Si non-C-based gas that is not heated by the thermalcatalysis body is merged with the introduction channel for introducingthe material-based gas.
 46. The film forming apparatus according toclaim 25, wherein at least a part of a surface of at least any one of aninner wall of a gas pipe, an inner wall of the showerhead and theradiation shielding member in the non-Si non-C-based gas introducingchannel comprises a material including at least one of the groupconsisting of Ni, Pd and Pt.
 47. The film forming apparatus according toclaim 5, wherein a thermal catalysis body is provided also in theintroduction channel for introducing the material-based gas, and thethermal catalysis body is controlled to be at a temperature below thetemperature at which the material-based gas decomposes.
 48. The filmforming apparatus according to claim 47, wherein when the material-basedgas comprises a gas whose molecular formula includes Si, the thermalcatalysis body provided in the introduction channel for introducing thematerial-based gas is controlled to be at a temperature of 500.degree.C.or below.
 49. The film forming apparatus according to claim 5, whereinan inner wall surface of a film deposition chamber constituting the filmdeposition space is heated.
 50. The film forming apparatus according toclaim 49, wherein the heating of the inner wall surface of the filmdeposition chamber is effected by a heater provided within the filmdeposition chamber.
 51. The film forming apparatus according to claim50, wherein, when the material-based gas comprises a gas whose molecularformula includes Si, the temperature of the heater provided within thefilm deposition chamber is controlled to be at 500.degree.C. or below.52. The film forming apparatus according to claim 5, wherein a passcondenser is provided in a power source circuit for heating the thermalcatalysis body.
 53. The film forming apparatus according to claim 5,wherein the substrate is in the form of a plate or a cylinder.
 54. A CVDapparatus comprising a plurality of vacuum chambers at least one ofwhich is a film deposition chamber for implementing a Cat-PECVD method,the film deposition chamber comprising: a first introduction channel forintroducing a non-Si non-C-based gas comprising a gas whose molecularformula excludes Si and C; a thermal catalysis body provided in thefirst introduction channel for heating the non-Si non-C-based gasintroduced thereinto; a second introduction channel for introducing amaterial-based gas comprising a gas whose molecular formula includes Siand/or C; a showerhead having a plurality of gas effusion ports fordirecting the material-based gas and the non-Si non-C-based gas heatedby the thermal catalysis body into a film deposition space separatelyfrom each other; and a nonplanar electrode connected to a radiofrequency power supply for forming a plasma space in the film depositionspace.
 55. A CVD apparatus according to claim 54, wherein the pluralityof vacuum chambers include a deposition chamber for forming a p-typefilm, a deposition chamber for forming an i-type film and a depositionchamber for forming an n-type film, the deposition chamber for formingan i-type film being capable of implementing the Cat-PECVD method. 56.The CVD apparatus according to claim 54, wherein at least one of theplurality of vacuum chambers is capable of implementing a Cat-CVDmethod.
 57. The CVD apparatus according to claim 54, wherein at leastone of the plurality of vacuum chambers is capable of implementing aPECVD method.
 58. The CVD apparatus according to claim 54, wherein theplurality of vacuum chambers include at least a prechamber.
 59. The CVDapparatus according to claim 54, wherein the plurality of vacuumchambers include at least a pre-chamber and a subsequent chamber. 60.The CVD apparatus according to claim 54, wherein the plurality of vacuumchambers include at least a heating chamber.
 61. The CVD apparatusaccording to claim 54, wherein the plurality of vacuum chambers arelinearly connected to one another in a row.
 62. The CVD apparatusaccording to claim 54, wherein the plurality of vacuum chambers areconnected to a core chamber present at least one in number.
 63. The CVDapparatus according to claim 54, wherein the film deposition chamber isof a deposit-down style.
 64. The CVD apparatus according to claim 54,wherein the film deposition chamber is of a deposit-up style.
 65. TheCVD apparatus according to claim 54, wherein the film deposition chamberis of a vertical style.
 66. A film formed on a substrate by a Cat-PECVDmethod, the Cat-PECVD method comprising the steps of: introducing anon-Si non-C-based gas comprising a gas whose molecular formula excludesSi and C into a first introduction channel; heating the non-Sinon-C-based gas introduced into the first introduction channel by athermal catalysis body; introducing a material-based gas comprising agas whose molecular formula includes Si and/or C into a secondintroduction channel; introducing the material-based gas and the non-Sinon-C-based gas heated by the thermal catalysis body separately fromeach other into a film deposition space through a showerhead having aplurality of gas effusion ports; and forming a plasma space in the filmdeposition space by means of a nonplanar electrode connected to a radiofrequency power supply, thereby depositing a film on the substrate. 67.The film according to claim 66, which is a Si-based film formed by theuse of a gas as the material-based gas which comprises a gas whosemolecular formula includes Si and excludes any gas whose molecularformula includes C, and a gas as the non-Si non-C-based gas whichcomprises H₂.
 68. The film according to claim 66, which is a Si-C-basedfilm formed by the use of a gas as the material-based gas whichcomprises a gas whose molecular formula includes Si and a gas whosemolecular formula includes C, and a gas as the non-Si non-C-based gaswhich comprises H₂.
 69. The film according to claim 66, which is aSi-N-based film formed by the use of a gas as the material-based gaswhich comprises a gas whose molecular formula includes Si, a gas as thenon-Si non-C-based gas which comprises H₂, and a gas whose molecularformula includes N that is included at least in either of thematerial-based gas and the non-Si non-C-based gas.
 70. The filmaccording to claim 66, which is a Si-O-based film formed by the use of agas as the material-based gas which comprises a gas whose molecularformula includes Si, and a gas as the non-Si non-C-based gas whichcomprises O₂.
 71. The film according to claim 66, which is a Si-Ge-basedfilm formed by the use of a gas as the material-based gas whichcomprises a gas whose molecular formula includes Si and a gas whosemolecular formula includes Ge, and a gas as the non-Si non-C-based gaswhich comprises H₂.
 72. The film according to claim 66, which is aC-based film formed by the use of a gas as the material-based gas whichcomprises a gas whose molecular formula includes C, and a gas as thenon-Si non-C-based gas which comprises H₂.
 73. A device using a filmdeposited on a substrate by a Cat-PECVD method, the Cat-PECVD methodcomprising the steps of: introducing a non-Si non-C-based gas comprisinga gas whose molecular formula excludes Si and C into a firstintroduction channel; heating the non-Si non-C-based gas introduced intothe first introduction channel by a thermal catalysis body; introducinga material-based gas comprising a gas whose molecular formula includesSi and/or C into a second introduction channel; introducing thematerial-based gas and the non-Si non-C-based gas heated by the thermalcatalysis body separately from each other into a film deposition spacethrough a showerhead having a plurality of gas effusion ports; andforming a plasma space in the film deposition space by means of anonplanar electrode connected to a radio frequency power supply, therebydepositing the film on the substrate.
 74. The device according to claim73, which is a photoelectric conversion device.
 75. The device accordingto claim 74, wherein the photoelectric conversion device is a solarcell.
 76. The device according to claim 73, which is a photoreceptordevice.
 77. The device according to claim 73, which is a display device.